"I'm devastated I'm unable to perform this week. Ursula took my mermaid voice, I've come down with horrible bronchitis," she tweeted, alongside a picture of Disney's famed sea witch villainess, who gave Ariel legs in exchange for her voice in The Little Mermaid.

The Grammy-winning star, 28, was set to take the stage in Seattle, Wash., on Wednesday, and in Vancouver, British Columbia, on Friday. The shows are part of her ArtRave: The Artpop Ball tour, which kicked off earlier this month in Fort Lauderdale, Fla.